🎓 Udemy Offline Player

Your Premium Local Learning Portal — Stream, Study & Master Any Course Offline

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🎬 See How It Works

Watch our quick walkthrough to see how easy it is to set up your local study portal.

▶️ Watch the guide on YouTube     |     📥 Download Free Demo Pack (ZIP)

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🔥 Buy Premium Udemy Courses — Unbelievably Cheap

Why pay $50 to $200 per course when you can get the exact same content for a fraction of the price?

We provide access to thousands of top-rated Udemy courses at the lowest prices available (see our course catalog for listings). Every purchase includes:

What You Get	Details
💰 Rock-Bottom Prices	Courses starting from just $3 to $5 — save up to 95% off retail
♾️ Lifetime Updates	If the instructor updates the course, you get the updates for free, forever
📥 Full Offline Access	Download the course once and learn anywhere — no internet required
🎬 Complete Content	All videos, high-quality subtitles, resources, and project attachments included
🤖 AI-Powered Player	Built-in AI translation, structured summarization, and chat assistant
⚡ Instant Delivery	Get your download link within minutes of placing an order
🛡️ 100% Safe	Clean, secure files with no malware and no subscription lock-ins

📲 Ready to Order? Contact Us Now!

Scan the QR code or click the image to message us on Telegram. Browse our [course catalog](./catalog.md) and place your order.
Special offer: First-time buyers get a special discount. Ask about our bundle deals.
Want to test first? Download our Free Demo Pack to try the offline player immediately.

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💎 Why Choose Us Over Buying Directly?

Compare how our local portal matches up against buying directly from Udemy:

Feature	Buying from Udemy	Learning with Us
Price	$50 to $200 per course	$3 to $5 per course
Updates	Only while subscribed or active	Lifetime updates included free
Offline Access	Limited mobile download only	Full desktop and mobile offline access
AI Features	None	Translation, summarization, and chat
Subtitles	English-only for most courses	Auto-translate subtitles to any language
Notes & Progress	Basic bookmarks	Timestamped notes + auto-save progress

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✨ Features Built for Power Learners

This player is built to help you learn faster and retain more information:

1. Intelligent Course Scanner: Point the player at your downloaded course folder. It automatically organizes lessons, chapters, and companion files into a clean sidebar menu.
2. Coordinated Tab View: Study side-by-side. If a lesson contains both a video and companion resources (like PDFs or cheat sheets), the player shows them together in coordinated tabs.
3. Custom HTML5 Video Stage:
   • Supports adjustable playback speeds (1x, 1.25x, 1.5x, 1.75x, 2x).
   • Browser hotkeys: Space (play/pause), Arrow Left/Right (skip 5 seconds), Arrow Up/Down (volume), and F (fullscreen toggle).
4. Interactive Notes Timeline: Type notes as you watch. The player pauses the video automatically while you type, and links each note to a click-to-seek timestamp.
5. Auto-Completion & Auto-Save: Lessons are marked complete at 90% watch progress. Your playback position saves every 5 seconds so you can resume exactly where you left off.
6. AI Subtitle Translation: Automatically translate English subtitle tracks to your native language using the built-in Gemini API.
7. Offline AI Summarization: Generate structured, bulleted summaries of video lessons. The summaries cache locally, letting you review them instantly without internet access.
8. Transcript-Grounded AI Chat: Ask questions about the lesson in the chat sidebar. The AI answers using the active subtitle transcript as context.

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🛠️ Developer Setup & Project Run

If you want to run the project locally, build it, or modify the code, follow these technical instructions.

Project Structure

udemy-player/
├── backend/
│   ├── server.js          # Express server with range-streaming, VTT conversion, & persistence APIs
│   ├── scanner.js         # File grouping and section sorting scanner
│   ├── progress_db.json   # Local user notes and completion database (JSON)
│   └── package.json       # Backend server dependencies
├── docs/                  # Technical specifications, implementation plans, and task lists
├── frontend/              # Vite React client
│   ├── src/
│   │   ├── components/    # CourseSelector, Sidebar, VideoPlayer, DocViewer, NotesPanel
│   │   ├── App.jsx        # App logic controller
│   │   ├── main.jsx       # Client entry
│   │   └── index.css      # Dark-mode styling tokens and layout rules
│   ├── vite.config.js     # Dev server proxy configuration
│   └── package.json       # Client dependencies
├── package.json           # Root runner scripts (starts concurrently)
├── telegram.jpg           # Telegram contact image/QR code
└── README.md              # Project documentation

Prerequisites

• Node.js (v16+)

1. Install Dependencies

Install all root, client, and server dependencies in one command:

npm run install:all

2. Start the Development Stack

Start both the API backend (Express on port 3003) and client frontend (Vite on port 3002) concurrently:

npm run dev

3. Open in Browser

Visit http://localhost:3002 to browse and play your courses.

4. Running the Desktop App (macOS DMG)

To package and run the application as a standalone desktop app on macOS:

1. Build the frontend and compile the package:

   npm run package

2. Drag Udemy Offline Player.app from dist-desktop/ to your /Applications folder.
3. If macOS Gatekeeper blocks the app from running, remove the quarantine attribute and self-sign it:

   # Remove the quarantine attribute
   xattr -cr /Applications/Udemy\ Offline\ Player.app
   
   # Self-sign the application
   codesign --force --deep --sign - /Applications/Udemy\ Offline\ Player.app

4. Launch the application normally from Applications or Launchpad.

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🔒 API Endpoints

• GET /api/course-content?path=<absolute-path>: Scans the folder and returns grouped chapters and lesson resources.
• GET /api/stream?path=<video-file-path>: Streams local video assets supporting Byte-Range header requests.
• GET /api/subtitle?path=<subtitle-file-path>: Feeds SubRip (.srt) contents converted to WebVTT format on-the-fly.
• GET /api/resource?path=<document-file-path>: Serves PDFs and HTML checkpoints securely.
• GET /api/userdata: Returns completion logs, note timelines, and active paths.
• POST /api/userdata/course: Scans and adds new course path to recent history.
• POST /api/userdata/progress: Updates completion states and watch logs.
• POST /api/userdata/notes: Inserts or updates annotation notes.
• DELETE /api/userdata/notes: Removes note entries from a lesson timeline.
• POST /api/userdata/settings: Saves application settings (such as the Gemini API Key).
• POST /api/translate-subtitle: Translates subtitles using the Gemini API.
• POST /api/summarize-lesson: Generates and caches lesson summaries.
• POST /api/chat-lesson: Chat assistant grounded in the subtitles transcript.
• POST /api/browse-folder: Launches native OS folder dialog window.

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